Among its many other projects, NASA is experimenting with spacecraft buses that can protect us from asteroids. Their DART (Double Asteroid Redirection Test) spacecraft bus was designed specifically to prove that we can defend ourselves from near-Earth objects (NEO) hits. NEOs often pass close to our planet, so the risk of one colliding with Earth exists. The DART experiment was very important for our efforts to build a global defense spacecraft system. Plus, there are spacecraft buses for Earth observation that give timely data on potential hazards.

Does Earth have an asteroid defence system?

Earth has the Planetary Defense program, which encompasses all the capabilities our planet needs to identify the possibility of a comet or NEO impacting us. Planetary Defense is also aimed at preventing or mitigating the possible effects of such an event. Program activities include:

● Finding NEOs and tracking them if they pose a threat to our planet.

● Characterizing asteroids and NEOs to determine their size, mass, shape, etc.

● Planning and implementing measures of disrupting or deflecting an object that has an impact trajectory with our planet by using spacecraft buses.

● Mitigating a potential impact’s effects to protect property and lives. This includes evacuation if spacecraft buses don’t succeed in their missions.

NASA is working hard to improve the Planetary Defense bus system so that we have better chances of defending ourselves with spacecraft buses in case of a hazardous situation. DART is an experiment standing proof that we are on the right path with this space bus program.

Is it possible to divert an asteroid?

Yes, Earth can now divert asteroids. This would not have been possible if NASA’s DART spacecraft bus had not changed the orbit of Dimorphous. Dimorphous had 560 feet in diameter. This successful experiment gives us a lot of hope about using spacecraft buses for redirecting asteroids. In the future, NASA expects Earth to have capabilities for any type of mission to divert an asteroid. Such ventures would be costly indeed, but the consequences of a NEO impacting us would cost much more. The good news is that many companies are making advanced spacecraft buses that can help detect NEOs. We can only hope that they will remain spacecraft observation missions and no NEO will come close enough to our planet to risk impact. Would it be possible to change the trajectory of such space objects if we were under threat? Let’s find out.

 So is it possible to change the trajectory of an asteroid?

Yes, it is now possible to change any NEO’s trajectory, and this is exactly what DART did. The spacecraft caused a 4% shift in the orbital motion of Dimorphos, changing its trajectory. The asteroid’s orbital period was shortened by about 32 minutes. Scientists and space experts are still investigating and acquiring spacecraft bus data from ground observatories across the world and radar facilities such as the NASA Jet Propulsion Laboratory’s Goldstone and the National Science Foundation’s Green Bank. They want to keep on observing what’s happening with the asteroid so that they can update their period measurements and make more precise changes regarding trajectory. Spacecraft bus images from when DART approached Dimorphous and from the LICIACube (Light Italian CubeSat for Imaging of Asteroids) will be analysed as well. These bus observations will help us learn more about how we can change NEO trajectories. According to NASA, we need more information about the asteroid’s surface and physical properties if we want to understand the recoil’s effect from eject. Knowing these things, we might perhaps be able to set new trajectories for asteroids soon.

How does NASA deflect asteroids?

As said before, NASA used the DART spacecraft to deflect the asteroid Dimorphous. As a result, spacecraft buses like DART are now our hope for a better future, where we are no longer terrified that an asteroid or any other NEO will impact Earth. Now back to how NASA deflected this asteroid. When DART was impacted, Dimorphous was 6.8 million miles or 11 million kilometres away from our planet and orbiting the Sun. The DART spacecraft was very light compared to the asteroid, which weighs around 11 billion pounds or 5 billion kg. Our spacecraft weighed only 1,210 pounds or 550 kg when it impacted Dimorphous. However, DART was a special model among spacecraft buses. It was designed to work like a kinetic impactor. This means that the spacecraft bus transferred its kinetic energy and momentum into the asteroid at impact. As a result, the asteroid’s orbit was altered with an advanced spacecraft bus. To understand better how NASA deflected Dimorphous, you should know that DART’s kinetic energy at impact was 10 billion joules. 

Most asteroids and other types of NEOs don’t pose a threat to our planet. Luckily, we now have spacecraft buses that can help us avoid such hazardous events. DART was one of these spacecraft buses that successfully accomplished its mission.